Windows: fix "Show in Explorer" opening Documents instead of the app's folder (#54)

* Fix Show in Explorer opening Documents for paths with spaces

reveal() built `/select,<path>` as one argument and passed it with
Command::arg, which quotes any argument containing a space. The Craft
apps' MSIs install under C:\Program Files, so Explorer received
"/select,C:\Program Files\...\app.exe", didn't recognise the switch and
opened its default folder, Documents.

The argument is now `/select,"<path>"`, with only the path quoted and
forward slashes turned into backslashes, passed with raw_arg so Rust
leaves it alone. The argument building is a plain function with unit
tests that run on every platform.

Fixes #39

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* Refuse a path with a quote in it; give the Explorer tests their own module

A " would end the quoted /select path early and pass the rest to Explorer as
switches. The module name clashed with the pgrep tests that landed in #81.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Fabio Lussi <198260595+itrycodinganditsbad@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>

crates/native/src/process.rs

@@ -160,16 +160,45 @@ pub fn reveal(path: &Path) -> Result<(), String> {
         cmd.arg("-R").arg(path);
         spawn_detached(cmd)
     } else if cfg!(windows) {
-        let mut arg = std::ffi::OsString::from("/select,");
-        arg.push(path);
-        let mut cmd = command("explorer");
-        cmd.arg(arg);
-        spawn_detached(cmd)
+        reveal_in_explorer(path)
     } else {
         open(path.parent().unwrap_or(path).as_os_str())
     }
 }
 
+#[cfg(windows)]
+fn reveal_in_explorer(path: &Path) -> Result<(), String> {
+    use std::os::windows::process::CommandExt;
+    let mut cmd = command("explorer");
+    // Passed raw: `arg` would wrap all of `/select,...` in quotes when the path has a space
+    // (`C:\Program Files\...`), and Explorer then ignores the switch and opens Documents.
+    // A quote in the path would end the quoted part early and let the rest reach Explorer as
+    // switches; no Windows path has one, so refuse it.
+    let arg = explorer_select_arg(path).ok_or_else(|| format!("{} isn't a usable path", path.display()))?;
+    cmd.raw_arg(arg);
+    spawn_detached(cmd)
+}
+
+#[cfg(not(windows))]
+fn reveal_in_explorer(_path: &Path) -> Result<(), String> {
+    Err("Explorer is only on Windows".into())
+}
+
+/// Explorer's `/select,"<path>"` argument as it goes on the command line: only the path is quoted,
+/// and forward slashes become backslashes, which Explorer needs to find the item. `None` for a path
+/// with a `"` in it.
+#[cfg_attr(not(windows), allow(dead_code))]
+fn explorer_select_arg(path: &Path) -> Option<std::ffi::OsString> {
+    let s = path.to_str()?;
+    if s.contains('"') {
+        return None;
+    }
+    let mut arg = std::ffi::OsString::from("/select,\"");
+    arg.push(s.replace('/', "\\"));
+    arg.push("\"");
+    Some(arg)
+}
+
 /// Whether a process started from inside `path` (an exe, an AppImage, or a `.app`) is running.
 pub fn is_running(path: &Path) -> bool {
     if cfg!(windows) {
@@ -252,3 +281,27 @@ mod tests {
         }
     }
 }
+
+#[cfg(test)]
+mod explorer_tests {
+    use super::*;
+
+    #[test]
+    fn explorer_select_quotes_only_the_path() {
+        let arg = explorer_select_arg(Path::new(r"C:\Program Files\PhotoCraft\photocraft.exe"));
+        assert_eq!(arg.unwrap(), r#"/select,"C:\Program Files\PhotoCraft\photocraft.exe""#);
+    }
+
+    #[test]
+    fn explorer_select_without_spaces() {
+        let arg = explorer_select_arg(Path::new(r"C:\Apps\photocraft.exe"));
+        assert_eq!(arg.unwrap(), r#"/select,"C:\Apps\photocraft.exe""#);
+        assert_eq!(explorer_select_arg(Path::new(r#"C:\Apps" /root,C:\x.exe"#)), None);
+    }
+
+    #[test]
+    fn explorer_select_uses_backslashes() {
+        let arg = explorer_select_arg(Path::new("C:/Users/A B/AppData/Local/ArtCraft Launcher/apps/photocraft.exe"));
+        assert_eq!(arg.unwrap(), r#"/select,"C:\Users\A B\AppData\Local\ArtCraft Launcher\apps\photocraft.exe""#);
+    }
+}